<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <script>
        //number  2**53-1 900XXXXXXX  16位
        // alert(1978437243866017794);
        alert("1978437243866017794");
    </script>
</body>
</html>